Sounds like your idmap file is being removed on reboot.
run testparm -sv | grep directory
and see where the lock directory is located. Make sure
the file winbindd_idmap.tdb in this directory is not
getting removed somehow on reboot. Check your winbindd
log file to see if there are errors there.
[EM
I set up a samba 3.0.2 server as member server in a NT4 Domain.
Winbind works great and I can "use" the NT Domain users for all I need.
At the moment I'm testing different shares with their permissions.
The Samba will also be our printserver, so I set up also cups and added
the printers to samba wi